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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Jan Kiszka <jan.kiszka@siemens.com>,
	Steven Rostedt <rostedt@goodmis.org>
Cc: RT <linux-rt-users@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH RT 3.18] ring-buffer: Mark irq_work as HARD_IRQ to prevent deadlocks
Date: Thu, 16 Apr 2015 17:33:23 +0200	[thread overview]
Message-ID: <552FD643.8070408@linutronix.de> (raw)
In-Reply-To: <552FD55F.8000105@siemens.com>

On 04/16/2015 05:29 PM, Jan Kiszka wrote:
> My patch is definitely not OK. It causes
> 
> [  380.372579] BUG: scheduling while atomic: trace-cmd/2149/0x00010004
> ...
> [  380.372604] Call Trace:
> [  380.372610]  <IRQ>  [<ffffffff81607694>] dump_stack+0x50/0x9f
> [  380.372613]  [<ffffffff8160413c>] __schedule_bug+0x59/0x69
> [  380.372615]  [<ffffffff8160a1d5>] __schedule+0x675/0x800
> [  380.372617]  [<ffffffff8160a394>] schedule+0x34/0xa0
> [  380.372619]  [<ffffffff8160bf7d>] rt_spin_lock_slowlock+0xcd/0x290
> [  380.372621]  [<ffffffff8160d8b5>] rt_spin_lock+0x25/0x30
> [  380.372623]  [<ffffffff8108fe39>] __wake_up+0x29/0x60

right. you must not take any sleeping locks in the hardirq context :)
This works for the no-hz-work thingy. It grabs raw locks and may cancel
one hrtimer which is marked irqsafe.

Sebastian

  reply	other threads:[~2015-04-16 15:33 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-04-16 14:06 [PATCH RT 3.18] ring-buffer: Mark irq_work as HARD_IRQ to prevent deadlocks Jan Kiszka
2015-04-16 14:12 ` Steven Rostedt
2015-04-16 14:26 ` Sebastian Andrzej Siewior
2015-04-16 14:28   ` Jan Kiszka
2015-04-16 14:57     ` Sebastian Andrzej Siewior
2015-04-16 15:31       ` Jan Kiszka
2015-04-16 15:10     ` Steven Rostedt
2015-04-16 15:29       ` Jan Kiszka
2015-04-16 15:33         ` Sebastian Andrzej Siewior [this message]
2015-04-16 16:28         ` [PATCH RT 3.18] irq_work: Provide a soft-irq based queue Jan Kiszka
2015-04-20  8:03           ` Mike Galbraith
2015-04-23  6:11             ` Mike Galbraith
2015-04-23  6:29               ` Jan Kiszka
2015-04-23  6:58                 ` Mike Galbraith
2015-04-23  7:14                   ` Jan Kiszka
2015-04-23  6:50               ` Jan Kiszka
2015-04-23  7:01                 ` Mike Galbraith
2015-04-23  7:12                   ` Jan Kiszka
2015-04-23  7:19                     ` Mike Galbraith
2015-04-23 21:00                       ` Steven Rostedt
2015-04-24  6:54                         ` Mike Galbraith
2015-04-24  9:00                           ` Jan Kiszka
2015-04-24  9:59                             ` Mike Galbraith
2015-04-25  7:20                             ` Mike Galbraith
2015-04-25  7:26                               ` Jan Kiszka
2015-05-18 19:52                                 ` Sebastian Andrzej Siewior

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